Grinding machine



March 15, 1932. w N APPLETON' 1,849,343

GRINDING MACHINE Filed May a, 1 929 2' Sheets-Sheet '1 INVENTOR March 15, 1932. w. N, APPLETON GRINDING MACHINE Filed May 8, 1929 2 Sheets-Sheet I I I I INVE N;R WW

Patented Mar. 15, 1932 UNITED STATES PATENTJOFFICE,

WALLACE N. APPLETON, OF GRAFTON, PENNSYLVANIA, ASSIGNOR, BY mnsNnAssmm,

or PITTSBURGH,PENNSYLVANIA, A ooaro- MENTS, TO THE MCKAY COMPANY, RATION OF PENNSYLVANIA GRINDING MAon ivE I, I

Application filed May 8, 1929. Serial No. 361,825.

My invention relates to grinding and polishi'ng machines, and more particularlyto those especially suitable for grinding and polishing metal bars, such as the frontand rear bumperbars of automobiles.

n In the manufacture of automobile bumpers of the flat bar type as distinguished from the tubular or channel bar bumpers, the bars are commonly formed of fiat spring steel which is curved to the propercontour and frequently have a loop or eye formed in both ends thereof in the case of front bumper bars and formed in at least one end ther'eof in the case of rear bumper bars or fender guards.

If the bumper-bars are to be plated with nickel, chromium, etc, it is necessary that they be quite smooth and this smoothing is effected by grinding and polishing the bars after they have been shaped to the desired form. Heretofore, it has been dificult to properly grind and polish curved bars, and bars with eyes formed in theirends, without considerable handwo1'k,'because of difiiculty in polishingthe' bars in proximity totheir eyes and in effecting uniform grinding and polishing through out the length of a curved bar." a Oneobj ect' of my invention is to provide an apparatus capable of more effectively grinding and polishing bars having'loop or eye portions. v

Still another object of my invention is to simplify and improve generally the art of grinding and-polishing metal bars.

One form which 'myi nvention may take is shown in the accompanying drawings, wherein Figure 1 is a side elei 'atio'nal viewof a grinding andpolishing machine; Fig. 2 is a view taken on the line II--II of Fig. 1, on an enlarged scaleyFig. 3 is a horizontal sec: tional viewof a portion of the apparatusof Figs. 1 and 2, and Fig. 4 is an elevational sectional view on anenlarged scale, of a portion of the apparatus of'Fig; 1. f

The apparatus consists of conveyer framework 5 at the opposite ends of which are mounted pulleys 6 and 7 for driving a conveyer belt 8, the pulley 7 being drivenfrom a suitable source of power by a driving pulley 9 and a driving belt 10. The upper flight of the conveyer belt 8 is supported by a bearing block 11 of wood or other suitable ma terial that is supported onthe web of an I-beam 12 forming part of the upper framework of the conveyer. Guide rails, 13 are mounted uponthe block 11 to prevent lateral displacement of the conveyor belt.

The conveyer belt 8 carries a series of brackets 14: that are secured thereto as shown more clearly in Figs. 2 and 4. A carrier arm 15 is pivotally secured to each of the brackets 14 and is forked at its outer end. A pin or rod 16 extends through the forked end of each arm 15 and such arm is normally held in the position shown in Fig. 4, by means of a spring 17 that is anchored to a plate 18 which is secured to the bracket 14. One end of the rod 16 carries an anti-friction roller 19 that is held, through the action of the spring 17, in engagement with a cam bar 21, so that, the arm 15, under the action of the said spring and the said cam'barwill oscillate about its pivot as hereinafter explained.

Theotherend of the pin16 serves to receive the eye 22 of a bumper bar '23 and to support the said bumper bar during movementthereof along the upper pathof travel 'ofthe conveyer belt, the bar being manually slidinto position upon the pin 16 at the right hand end of the conveyor as viewed in Fig. 1

and removed therefrom at the opposite endthereof.

Grinding and polishing wheels 25, and 26' are supported uponpedestals 27 and 28 respectively, and are driven by motors 29;

These grinding wheels may be of emery or axes of the wheels and 26 are fixed, and

'ing wheels 25 and 26.

i are supported upon crank arms 33 (Fig. 3)

that form extensions of sleeve-like bearing members 34 each of which is pivotally mounted upon a pin or shaft 35 that is secured to an upright 36. A drum-like extension 37 is secured to each of the presser wheels, 31 and 32, and each wheel is normally held in the position shown in Fig. 4 by means of a weight 38 that is connected, through a strap 39, to the drum, stop members 41 and 42 being provided on a post 43 and the drum 37 respectively, to limit backward rotative movement of the wheel under the influence of the weight A weight arm 44 is connected to the sleeve 34 and has notches therein wherein a weight 45 may be supported, at different positions longitudinally of the arm, to vary the upward pressure of the presser wheels, so that bumper bars will be held against the wheels and 26 with a desired degree of pressure. 7

With the wheels 31 and 32 positioned as 7 shown in Figs. 4 and 1, respectively, notches 46 provided thereinwill be in position to re ceive the eyes 22 of the bumper bars 23 and the pull exerted bysuch eyes, during advance movement of the conveyer and the bumper bars will cause the presser wheels to be rotated and to press the bars 23 into engagement with the grinding wheels 25 and 26, the degree of pressure depending upon the position of the weight on the arm 44. As soon as a bumperbar has passed completely from engagement with the wheels 25 and 31, for instance, therwheel 31 will be returned to its normal position, under the action of the wei ht 38, ready to receive the eye of the succeeding bump er. v

I After the forward end of the bumper bar has passed from beneath the grindingwheel 25 and the wheel'26, the carrier arm 15t0 which said bar is connected will be deflected downwardly by the cam surfaces 21a and 21b of the bar 21, through contact of such surfaces with the roller 19, thus causing the bar to engage thegrinding wheel 25 (for instance) onlyat points opposite to the wheel 31, and insuring that there will not be excessive polishing of the curved portion of the bumper through tendency of the arm 15 and the spring17 to maintain it in too high a plane after passing from between the wheels.

From the foregoing, it will be seen that not only are all the forwardly-exposed portions of the eye 22 fully ground and polished, but that all portions of the bar 23, whether curved or straight, are polished to a uniform degree by reason of the uniformity of pressure exertedthereon by the presser wheels 31 and 32 and by reason of the vertical movements of the carrier arms 15 previous to and after it passes the presser wheels and the grinding wheels.

In the appended claims, it will be understood that the word grinding is employed in a broad sense to include also smoothing operations such as polishing or bufiing.

I claim as my invention: 7

1. Grinding apparatus for bars having enlarged portions at one end, comprising a grindingwheel, a rotatably mounted presser member for holding-work in engagement with said grinding wheel, a recess on said presser member for receiving the said enlarged portions of bars, a carrier for the bars, and means for returning the presser member to initial position after it has been rotated by passage of the said enlarged portions.

2. Grinding apparatus for bars having'enlarged portions at one end, comprising a grinding wheel, a rotatably mounted presser member engaging. against the under-surface of the work for holding work in engagement with said grinding wheel, a recess on said presser member for receiving the said enlargedportions of bars, a carrier for the bars, stop means for holding said presser member in position to receive said enlarged portions of the bars, and means for yieldably holding said member against said stop.

3. Apparatus for grinding a metal bar having an ofiset portion on one end thereof, comprising a grinding wheel, a conveyer, an outwardly-extended carrier arm on said conveyer movable relatively to the conveyer and having means thereon for engaging said offset portion, and means disposed adjacent to the grinding wheel and affording support for the other portions of the bar during movement past said wheel. I

4. Apparatus for grinding curved bumper bars having eye portions in oneend thereof, comprising a grinding wheel, a conveyer, carrier arms onthe conveyers having means for effecting detachable connection with said eye portions, means for yieldably urging said arms outwardly to effect grinding engage ment between the said eye'portions andthe said wheeel during traveling movement of the conveyer, and a presser member independent of the conveyer for supporting the other portions of thebars during movement past said wheel.

5. Apparatus for grinding bars, comp-rising a grinding wheel, a presser member for holding-the bars in engagement with said wheel,a conveyer for continuously advancing the bars between the said member and the said wheel, outwardly extended carrier arms on the conveyer for pivotally supporting one end of the bars, and means for yieldably projecting said arms.

6. Apparatus for grinding bars, comprising a grinding wheel, a presser member for holding the bars in engagement with said wheel, a conveyer for continuously advancing the bars between the said member and the said wheel, outwardly-extended carrier arms on the conveyer for pivotally supporting one end of the bars, means for yieldably projecting said arms, and means for depressing the said arms to change the angular position of the bars relative to the grinding wheel during a grinding operation.

In testimony whereof I, the said WALLACE N. APPLETON, have hereunto set my hand.

WALLACE N. APPLETON. 

